Abstract
Antigenic relationships among seven California group strains were studied by a plaque-reduction neutralization test (PRNT). Cross-reactions occurred in most cases but three subgroups were noted: (1) the major serogroup contained the viruses of California encephalitis, LaCrosse, Snowshoe Hare and rahya (including the Lumbo strain) whereas (2) Jamestown Canyon and (3) Trivittatus viruses were distinct. There was no significant difference between the PRNT results in mammalian (PS) cells incubated at 37 °C and amphibian (XTC-2) cells incubated at 28 °C. Trivittatus virus failed to produce plaques in XTC-2 cells.
* Present address: Institute of Parasitology, Czechoslovak Academy of Sciences, 166 32 Prague, Czechoslovakia.